Functionalization of Titanium surface with Chitosan via silanation: 3D CLSM imaging of cell biocompatibility behaviour

Introduction Biocompatibility ranks as one of the most important properties of dental materials. One of the criteria for biocompatibility is the absence of material toxicity to cells, according to the ISO 7405 and 10993 recommendations. Among numerous available methods for toxicity assessment; 3-dimensional Confocal Laser Scanning Microscopy (3D CLSM) imaging was chosen because it provides an accurate and sensitive index of living cell behavior in contact with chitosan coated tested implants. Objectives: The purpose of this study was to investigate the in vitro biocompatibility of functionalized titanium with chitosan via a silanation using sensitive and innovative 3D CLSM imaging as an investigation method for cytotoxicity assessment. Methods The biocompatibility of four samples (controls cells, TA6V, TA6V-TESBA and TA6V-TESBAChitosan) was compared in vitro after 24h of exposure. Confocal imaging was performed on cultured human gingival fibroblast (HGF1) like cells using Live/Dead® staining. Image series were obtained with a FV10i confocal biological inverted system and analyzed with FV10-ASW 3.1 Software (Olympus France). Results Image analysis showed no cytotoxicity in the presence of the three tested substrates after 24 h of contact. A slight decrease of cell viability was found in contact with TA6V-TESBA with and without chitosan compared to negative control cells. Conclusion Our findings highlighted the use of 3D CLSM confocal imaging as a sensitive method to evaluate qualitatively and quantitatively the biocompatibility behavior of functionalized titanium with chitosan via a silanation. The biocompatibility of the new functionalized coating to HGF1 cells is as good as the reference in biomedical device implantation TA6V

Tissue Engineering for Periodontal Ligament Regeneration: Biomechanical Specifications

The periodontal biomechanical environment is very difficult to investigate. By the complex geometry and composition of the periodontal ligament, its mechanical behavior is very dependent on the type of loading (compressive vs. tensile loading; static vs. cyclic loading; uniaxial vs. multiaxial) and the location around the root (cervical, middle, or apical). These different aspects of the periodontal ligament make it difficult to develop a functional biomaterial to treat periodontal attachment due to periodontal diseases. This review aims to describe the structural and biomechanical properties of the periodontal ligament. Particular importance is placed in the close interrelationship that exists between structure and biomechanics: the periodontal ligament structural organization is specific to its biomechanical environment, and its biomechanical properties are specific to its structural arrangement. This balance between structure and biomechanics can be explained by a mechanosensitive periodontal cellular activity. These specifications have to be considered in the further tissue engineering strategies for the development of an efficient biomaterial for periodontal tissues regeneration

Magnetic anisotropy Berry's phase

By considering the intrinsic anisotropy, present in almost all magnetic systems, as a perturbation to the usual Zeeman term, we show that the spin-spin dipolar interaction also known as zero-field splitting (ZFS) leads to an extra geometrical phase in addition to the conventional Berry's phase. Furthermore, we suggest some ways to observe the energy shift in electron paramagnetic resonance spectra due to Berry's phase and how we can separate it from the conventional Zeeman Berry's phase. One of the authors (MM) dedicates this work to the memory of his mother, Djabou Zoulikha, who died on 3 February 2019

Mechanical characteristic and biological behaviour of implanted and restorative bioglasses used in medicine and dentistry: A systematic review

International audienceObjectiveNowadays bioactive glasses are finding increasing applications in medical practice due to their ability to stimulate re-mineralisation. However, they are intrinsically brittle materials and the study of new compositions will open up new scenarios enhancing their mechanical properties and maintaining the high bioactivity for a broader range of applications. This systematic review aims to identify the relationship between the composition of bioactive glasses used in medical applications and their influence on the mechanical and biological properties.MethodsVarious electronic databases (PubMed, Science Direct) were used for collecting articles on this subject. This research includes papers from January 2011 to March 2016. PRISMA guidelines for systematic review and meta-analysis have been used. 109 abstracts were collected and screened, 68 articles were read as relevant articles and a total of 22 papers were finally selected for this study.ResultsMost of the studies obtained enhanced mechanical properties and the conservation of bioactivity behaviours; although a lack of homogeneity in the characterization methods makes it difficult to compare data.SignificanceNew compositions of bioactive glasses incorporating specific ions and the addition in polymers will be the most important direction for future researches in developing new materials for medical applications and especially for dentistry

In vitro biocompatibility of a dentine substitute cement on human MG63 osteoblasts cells: Biodentine™ versus MTA ®

The authors also wish to express their appreciation to Beatrice Burdin, PhD, at the Microstructures Technology Center of University Claude Bernard Lyon1 for assistance with the SEM study. The AFM study was supported by the Characterization of Interactions Platform of the Nanobio Program, Grenoble University. We gratefully acknowledge the assistance on the English checking from Dr Huw Jones BSc PhD MRSC, Senior Lecturer in Chemistry for Environmental Science and Public Health, Middlesex University (UK).International audienceAimTo compare the in vitro biocompatibility of Biodentine and White ProRoot((R)) mineral trioxide aggregate (MTA((R))) with MG63 osteoblast-like cells and to characterize the cement surface. MethodologyA direct contact model for MG63 osteoblast-like cells with cements was used for 1, 3 and 5days. Four end-points were investigated: (i) cement surface characterization by atomic force microscopy (AFM), (ii) cell viability by MTT assay, (iii) protein amount quantification by Bradford assay and (iv) cell morphology by SEM. Statistical analyses were performed by analysis of variance (anova) with a repetition test method. ResultsThe roughness of the cements was comparable as revealed by AFM analysis. The MTT test for Biodentine was similar to that of MTA((R)). Biodentine and MTA((R)) induced a similar but slight decrease in metabolic activity. The amount of total protein was significantly enhanced at day three (P<0.05) but slightly decreased at day five for both tested samples. Biodentine was tolerated as well as MTA((R)) in all cytotoxicity assays. SEM observations showed improvement of cell attachment and proliferation on both material surfaces following the three incubation periods. ConclusionThe biocompatibility of Biodentine to bone cells was comparable to MTA((R))